Observations on the distribution of chlorinated hydrocarbons in Atlantic Ocean organisms

Industrial polychlorobiphenyls (PCBs) and the DDT family (t-DDT) were measured in several species of organisms collected from the open Atlantic Ocean between 66°N and 35°S latitude. All the organisms had higher concentrations of PCBs than t-DDT. Many trophic levels were represented in the collections, but the analytical data offer no support for food chain magnification among gilled organisms...

Ursinus College Bulletin, Fall 1981

The more things change... • What are we doing here and how do we teach the students to do it, too? • Prescribing a path for the preprofessional • Robbing the cradle • To be or not to be: Is the supermom role for me? • New faculty appointments • Staff appointments • Ursinus begins 112th year • Watch for Winterfest! • Back to BASIC • Watts new • Go for Baroque • Kicking off a new league • Phi Psilebration • Looking for bookings • Sports scoreboard • Fall Forum program • ZXtra • News notes • Births • Marriages • Deaths • Round and round we go • Ellwood S. Paisley \u2713: The consummate Ursinus manhttps://digitalcommons.ursinus.edu/new_bulletin/1030/thumbnail.jp

Ursinus College Bulletin, Spring 1982

Ursinus plans for the future: Targets and strategies • Setting the stage • Women\u27s work • Book sale benefits Myrin Library • Name that tune • Art exhibited in Myrin • Federal funding and financial aid • Brown named football coach • G.E. Chairman to address graduates • Note of thanks • Alumni named to administration • Want ads • U.C. goes to U.N. • Winterfest! • Summer study in Japan • Frat fund • Evenings and weekends: Prime time at Ursinus • Abroad view • $500,000 grant • Arnold to assume development post • Homecoming • Founders Day • News notes • 25th reunion report • Evening School • Marriages • Births • Deaths • New alumni directory to be publishedhttps://digitalcommons.ursinus.edu/new_bulletin/1031/thumbnail.jp

Non‐native ants drive dramatic declines in animal community diversity: A meta‐analysis

Non‐native ants can cause ecosystem‐wide ecological change, and these changes are generally assumed to be negative. Despite this, the evidence base has never been holistically synthesised to quantify whether and to what degree non‐native ants impact native species diversity. In this study, we performed a meta‐analysis of the effects of ant invasion on animal communities. We extracted data from 46 published articles investigating abundance (156 effect sizes) and richness (53 effect sizes) responses of animal taxa to ant invasion in locations relatively unimpacted by other stressors (e.g. human disturbance, other non‐native species) to help isolate the effects of invasion. Overall, local animal diversity declined severely, with species abundance and richness lower by 42.79% and 53.56%, respectively, in areas with non‐native ants compared with intact uninvaded sites. We then combined responses of individual animal taxa extracted from an article into a single response to represent the ‘community’ abundance (40 effect sizes) or richness (28 effect sizes) response to non‐native ants represented in each article. Local communities decreased substantially in total abundance (52.67%) and species richness (53.47%) in invaded sites. These results highlight non‐native ants as the drivers, rather than passengers, of large net‐negative reductions to animal community diversity in relatively undisturbed systems around the world, approximately halving local species abundance and richness in invaded areas. Improved international prevention processes, early detection systems harnessing emerging technologies, and well‐designed control measures deployable by conservation practitioners are urgently needed if these effects are to be mitigated, prevented or reversed

Towards More Precise Survey Photometry for PanSTARRS and LSST: Measuring Directly the Optical Transmission Spectrum of the Atmosphere

Motivated by the recognition that variation in the optical transmission of the atmosphere is probably the main limitation to the precision of ground-based CCD measurements of celestial fluxes, we review the physical processes that attenuate the passage of light through the Earth's atmosphere. The next generation of astronomical surveys, such as PanSTARRS and LSST, will greatly benefit from dedicated apparatus to obtain atmospheric transmission data that can be associated with each survey image. We review and compare various approaches to this measurement problem, including photometry, spectroscopy, and LIDAR. In conjunction with careful measurements of instrumental throughput, atmospheric transmission measurements should allow next-generation imaging surveys to produce photometry of unprecedented precision. Our primary concerns are the real-time determination of aerosol scattering and absorption by water along the line of sight, both of which can vary over the course of a night's observations.Comment: 41 pages, 14 figures. Accepted PAS

Herbivorous dietary selection shown by hawfinch (Coccothraustes coccothraustes) within mixed woodland habitats

Knowledge of diet and dietary selectivity is vital, especially for the conservation of declining species. Accurately obtaining this information, however, is difficult, especially if the study species feeds on a wide range of food items within heterogeneous and inaccessible environments, such as the tree canopy. Hawfinches (Coccothraustes coccothraustes), like many woodland birds, are declining for reasons that are unclear. We investigated the possible role that dietary selection may have in these declines in the UK. Here, we used a combination of high-throughput sequencing of 261 hawfinch faecal samples assessed against tree occurrence data from quadrats sampled in three hawfinch population strongholds in the UK to test for evidence of selective foraging. This revealed that hawfinches show selective feeding and consume certain tree genera disproportionally to availability. Positive selection was shown for beech (Fagus), cherry (Prunus), hornbeam (Carpinus), maples (Acer) and oak (Quercus), while Hawfinch avoided ash (Fraxinus), birch (Betula), chestnut (Castanea), fir (Abies), hazel (Corylus), rowan (Sorbus) and lime (Tilia). This approach provided detailed information on hawfinch dietary choice and may be used to predict the effects of changing food resources on other declining passerines populations in the future

Temporal variation in spider trophic interactions is explained by the influence of weather on prey communities, web building and prey choice

1. Generalist invertebrate predators are sensitive to weather conditions, but the relationship between their trophic interactions and weather is poorly understood. This study investigates how weather affects the identity and frequency of spider trophic interactions over time, alongside prey community structure, web characteristics and prey choice. 2. Spiders (Linyphiidae and Lycosidae) and their prey were collected from barley fields in Wales, UK from April to September 2017-2018. The gut contents of 300 spiders were screened using DNA metabarcoding, analysed via multivariate models, and compared against prey availability using null models. When linyphiids were collected from webs, the height and area of webs were recorded and compared against weather conditions. 3. Trophic interactions changed over time and with weather conditions, primarily related to concomitant changes in prey communities. Spiders did, however, appear to mitigate the effects of structural changes in prey communities through changing prey preferences according to prevailing weather conditions, possibly facilitated by adaptive web construction. 4. Using these findings, we demonstrate that prey choice data collected under different weather conditions can be used to refine inter-annual predictions of spider trophic interactions, although prey abundance was secondary to diversity in driving the diet of these spiders. By improving our understanding of the interaction between trophic interactions and weather, we can better predict how ecological networks are likely to change over time in response to variation in weather conditions and, more urgently, global climate change

Seasonal and ontological variation in diet and age-related differences in prey choice, by an insectivorous songbird

The diet of an individual animal is subject to change over time, both in response to short-term food fluctuations and over longer time scales as an individual ages and meets different challenges over its life cycle. A metabarcoding approach was used to elucidate the diet of different life stages of a migratory songbird, the Eurasian reed warbler (Acrocephalus scirpaceus) over the 2017 summer breeding season in Somerset, the United Kingdom. The feces of adult, juvenile, and nestling warblers were screened for invertebrate DNA, enabling the identification of prey species. Dietary analysis was coupled with monitoring of Diptera in the field using yellow sticky traps. Seasonal changes in warbler diet were subtle, whereas age class had a greater influence on overall diet composition. Age classes showed high dietary overlap, but significant dietary differences were mediated through the selection of prey; (i) from different taxonomic groups, (ii) with different habitat origins (aquatic vs. terrestrial), and (iii) of different average approximate sizes. Our results highlight the value of metabarcoding data for enhancing ecological studies of insectivores in dynamic environments

Observational and metabarcoding approaches reveal the ecology, natural history and conservation status of Scolopendra abnormis, a threatened centipede endemic to Mauritius

The Serpent Island centipede Scolopendra abnormis is a threatened centipede species found on only 2 small islands in the Indian Ocean: Round Island, located 22.5 km northeast of Mauritius, and Serpent Island, 4 km northwest of Round Island. Current understanding of its ecology is based on limited direct observations from 30 yr ago. Round Island has since undergone significant habitat restoration. Hyperabundant non-native ants are also present, which may impact centipede nesting behaviour, ecology, and survival. Recent methodological advances, such as high-throughput sequencing of dietary DNA, can extend our understanding of invertebrate ecology and provide data complementary to direct observation. Using a combination of dietary metabarcoding and observational approaches, we provide new insights into the ecology and natural history of this threatened invertebrate predator. S. abnormis nest most consistently in the root network found beneath endemic Pandanus vandermeeschii trees. They are also found in areas with good soil cover, herbaceous growth, and areas of bare rock slab. Only 4 of 43 centipedes in this study were found near an ant foraging trail, which may have significant implications for S. abnormis nesting habits. These centipedes primarily consume insect prey (particularly taxa within Lepidoptera, Hymenoptera, Diptera), irrespective of centipede body size. A quarter of centipedes also consumed endemic lizards. We also found marked differences in diet composition between wet and dry seasons arising from the changing availability of prey. We provide additional natural history observations and conclude by suggesting conservation actions that would help better understand and safeguard S. abnormis populations

Where is the UK's pollinator biodiversity? The importance of urban areas for flower-visiting insects

Insect pollinators provide a crucial ecosystem service, but are under threat. Urban areas could be important for pollinators, though their value relative to other habitats is poorly known. We compared pollinator communities using quantified flower-visitation networks in 36 sites (each 1 km2) in three landscapes: urban, farmland and nature reserves. Overall, flower-visitor abundance and species richness did not differ significantly between the three landscape types. Bee abundance did not differ between landscapes, but bee species richness was higher in urban areas than farmland. Hoverfly abundance was higher in farmland and nature reserves than urban sites, but species richness did not differ significantly. While urban pollinator assemblages were more homogeneous across space than those in farmland or nature reserves, there was no significant difference in the numbers of rarer species between the three landscapes. Network-level specialization was higher in farmland than urban sites. Relative to other habitats, urban visitors foraged from a greater number of plant species (higher generality) but also visited a lower proportion of available plant species (higher specialization), both possibly driven by higher urban plant richness. Urban areas are growing, and improving their value for pollinators should be part of any national strategy to conserve and restore pollinators